Dutta Sanghamitra, Ray Lalitagauri
Department of Food Technology & Biochemical Engineering, Jadavpur University, Kolkata, India.
Appl Biochem Biotechnol. 2009 Oct;159(1):142-54. doi: 10.1007/s12010-009-8543-x. Epub 2009 Feb 6.
A bacterial strain isolated from spoiled coconut and identified as Bacillus cereus was found capable of producing alkaline thermostable extracellular lipase. Optimum temperature, time, and pH for enzyme substrate reaction were found to be 60 degrees C, 10 min, and 8.0 respectively. Common surfactants except Triton X 100 and cetyltrimethylammonium bromide have no or very little inhibitory effects on enzyme activity. The enzyme was found to be stable in presence of oxidizing agents and protease enzyme. The maximum lipase production was achieved at 30-33 degrees C, pH 8.0 on 24 h of fermentation using 50 ml medium in a 250-ml Erlenmeyer flask. The superior carbon and nitrogen sources for lipase production were starch (2%) and ammonium sulfate (nitrogen level 21.2 mg/100 ml), peptone (nitrogen level 297 mg/100 ml), and urea (nitrogen level 46.62 mg/100 ml) in combination, respectively. The maximum enzyme activity obtained was 33 +/- 0.567 IU/ml.
从变质椰子中分离出的一株细菌,经鉴定为蜡样芽孢杆菌,发现其能够产生碱性耐热胞外脂肪酶。酶底物反应的最适温度、时间和pH值分别为60℃、10分钟和8.0。除了 Triton X 100和十六烷基三甲基溴化铵外,常见的表面活性剂对酶活性没有或只有很小的抑制作用。发现该酶在氧化剂和蛋白酶存在的情况下是稳定的。在250毫升锥形瓶中使用50毫升培养基,在30 - 33℃、pH 8.0条件下发酵24小时,可实现脂肪酶的最大产量。脂肪酶生产的优质碳源和氮源分别是淀粉(2%)以及硫酸铵(氮含量21.2毫克/100毫升)、蛋白胨(氮含量297毫克/100毫升)和尿素(氮含量46.62毫克/100毫升)的组合。获得的最大酶活性为33±0.567 IU/ml。